Apparatus for coking petroleum



y 8, 1941. R. WQGARMAN 2,248,677

' I APPARATUS FOR COKING PETROLEUM Filed June 5, 1939 2 Sheets-Sheet 112 4o E 3'6 J 7? I J a 2? an 42 27 22 re I /7 /4 l7 4/ 27 I 7 42 ==CI= OI 8 v 3 INVENTOR:

- BY 9 W 54/241444 I Km- ATTORNEY.

July 8, 1941. R. W. GARMAN 2.248577 APPARATUS FOR COKING PETROLEUM FiledJune 5, 1939 2 Sheds-Sheet 2 i 29 l I I I I INVENTOI: G 2444/) ATTORNEY.

' Patented July 8, 1941 UNITED STATES PATENT OFFICE APPARATUS FOR comePETROLEUM Reed Waldo Garman, South Pasadena, Calif.

Application June 5,1939, Serial No. 277,438

11 Claims.

It is an object of the invention to provide apparatus for the simplifiedtreatment of heavy petroleums so that a substantially continuous processof converting such heavy oils into lighter oils and coke can be had withminimum shutdown periods for cleaning out coke.

Another object is to provide an improved apparatus for substantiallycontinuous operation in cracking heavy oils to produce lighter oils andcoke. 1

The invention will be better understood by ref erence to the drawings,in which:

Fig. 1 is an elevation, partly in section, showing one form of suitableapparatus;

Fig. 2 is a modification of Fig. 1.

Fig. 3 is an interior view along the lines 3-3 of Fig. 1.

Fig. 4 is a side view, partly in section, showing details ofconstruction.

The invention will be described with reference to the use of theapparatus for treating heavy petroleums to produce lighter oils andcoke, although it will be understood that the invention is not limitedto this specific use.

Heretofore, in the so-called coking stills used in the art for treatingheavy oils, the oil has been preheated to above its cracking temperatureand discharged into a receptacle, or evaporator, where the crackingtemperature is maintained for the production of lighter oils and theinevitable deposition of coke which eventually accumulates as a solidmass so that long and costly removal is necessary for the practicallysolidified mass.

Petroleum coke has the attribute of adhering strongly to the usual steelstills in refineries and with the heavy petroleums high in sulphur itis,

impossible to remove the coke residues from coking stills except bybreaking the solidified coke mass.

Further, inasmuch as the bulk of the. sulphur remains in the coke, highcorrosion efiects cause rapid deterioration of such ordinary apparatusand there is consequently a thickness of coke left on the metal which ispractically impossible to remove and which serves as a base onsuccessive coking charges whereon the coke quickly reaccumulates.

In other words, in ordinary coking stills, the coke is never formed soas to be easily broken and removed to leave a clean metal surface.

More particularly, in the so-called delayed cokers recently gone intouse forcoking heavy oils, it is usual to quickly heat the oil well aboveits cracking temperature and then quickly discharge the oil into thebottom of a receptacle, or evaporator, wherein'the heat in the oil inexcess of the heat finally retained in the residue at cokingtemperatures is sufiicient to convert the heavy oil to lighter oils andcoke, provided there is suflicient time allowed after thus charging thereceptacle before the receptacle is opened to remove the coke whichforms a single deep mass. Such coke is hard to break and remove, thesocalled cable method often being used in which a spirally coiled metalcable is first placed in the empty receptacle around which the cokeforms and when the-coking is completed, the ends of the coil are pulledout through an opened manhole thus fracturing the coke which is thenmanually removed. Coke removal from such delayed cokers is alsoaccomplished by a so-called hydraulic method. v

I have discovered that, by the use of certain flexible,corrosion-resistant alloys, the deposition of a mass of coke thereon isimmaterialto its ready fracture and easy removal while carrying on acoking process.

When such alloys are formed and arranged, a plurality of coking stillsassure continuous operations when coking the most refractory, highsulphur, heavy petroleums.

In this respect, it'must be remembered that coking stills are used torecover valuable products, such as gasoline, kerosene, gas oil and fueloil from viscous heavy petroleums, or residuums, which alone is oflittle value for ordinary cracking operations because its conversionquickly plugs the whole apparatus with coke and which, further, haslittle adapt..bility for fuel oils due to its viscous nature and highsulphur content. Such heavy oils may run from about eight to fifteendegrees Baum gravity, and ordinarily, as crude oils, contain nogasoline.

Referring to Fig. 1; if such a heavy oil is quickly heated to a degreewell above its cracking temperature as, for instance, by passage throughthe tubes of any well known oil refinery heating apparatus, and is thenquickly discharged into coking still IQ of this invention by pipe ll, sothat the time during which the oil is being thus heated in such tubes isinsufiicient to cause any substantial degree of cracking whereby cokewill be deposited in such tubes, the thus heated heavy oil may be thenfurther heated in its downward passage through still H! by indirect heatso as to produce lighter oils and coke in a relatively short time, thecoke produced being exceptionally porous, brittle, and easily removable.As there would normally be a large temperature drop in the ordinarydelayed cokers, such drop is herein eliminated by continuous indirectheating with hot vapors and the lengthy time of coking is alsoeliminated.

Coking still l comprises an outer shell I! of steel or iron capable ofwithstanding a desired superatmospheric pressure which is linedsubstantially throughout its length with corrosion proof, flexible sheetmetal 13 formed into suitable corrugations and welded completely roundits upper and lower ends to shell I! to form a space M to which isjoined pipe 15; sheet l3 being also spot welded at suitable pointsthroughout its length to shell l2 for proper strength and support.

The form of corrugations in sheet l3 are shown as longitudinal, but anysuitable corrugations are effective to cause movement of sheet l3responsive to a fluid pressure introduced into space H through pipe l5,such as air, steam, or the like.

Sheet I3 is formed of a ductile, flexible, noncorroding alloy havinglong life under repeated stresses, such as the nickel-copper-iron alloyknown as Monel metal, capable of withstanding temperatures as high as1000 F. or higher without permanent deformation. Other nickel alloys areespecially valuable and the alloy commercially known as inconel metal,containing approximately 80% nickel, 14% chromium, and 6% iron, is veryuseful when processes are used requiring high resistance to oxidationunder 2000 F. together with resistance to sulphur, hardness under impactand little fatigue under high temperatures.

These alloys are merely illustrative and the invention comprehends theuse of any metal, or alloy, to suit a given condition of use.

Supported within the inflatable sheet l3 are a plurality of cones, orhoppers, IS, a description of one of which applies to all.

Each cone I is formed of a suitable flexible metal or alloy, asdescribed, having radial corrugations terminating in a substantiallycircumferential line where it is tightly welded to sheet l3, the conehaving its lower end controllably free and relatively restrictedcompared to its welded upper end; said lower end being regulablyexpanded as desired.

At spaced intervals on the under side of cone iii are lightly weldednarrow metal strips l1 which are preferably set in a corrugation to giveadded strength and certain of said strips form a stiffer base forconnection on the other side of the corrugation to an operating linkagecomprising a plurality of arms l8, pivoted at one end to certainstiffened corrugations and at the other end to a collar 19 slidablyencircling a central supporting stem 20, moreclearly shown in Fig. 3.

Collar I9 is provided with trunnions 2| journalling the end of a yoke 22fixed on a shaft 23 adapted to be oscillated exteriorly by lever 24through a stufling box 25, whereby the smaller end of cone l6 may beexpanded and contracted.

Inasmuch as accumulation of coke on any part of the interior of stillII] in any quantity is not desired, all operating parts may be made ofnoncorroding alloys as described, and stem 20 may be further coveredbetween collars I9 with corrugated flexible metal 26 which iscylindrical for a distance suflicient to permit collars l9 to slide.Below each collar IS in each cone I6 is flxed a plug 2'! formed of twooppositely concaved corrugated disks 2B, which may be formed as a weldedextension of covering 26 and welded circumferentiaily to supportingplates 29 and 30 having perforations 3| and 32 therein respectively, andthe periphery of plug 21 is fashioned to fit loosely into thecorrugations in cone l6.

Within a plug 21, stem 20 is perforated at 34 and its lower ends areconnected to a pipe 35 for the purpose of applying a fluid pressure todisks 28 as well as to the corrugated covering 26. Stem 20 is suitablysupported at the upper and lower ends of still ID by spiders 36 and 37respectively.

A dump cover 38 is placed at the bottom of still l0 and an inlet pipe 39serves to introduce a heated gaseous medium while such medium iswithdrawn with evolved products through pipe 40.

In the operation of the device for cracking and coking heavy petroleums,the oil heated very quickly to the desired degree, say from 900 F. to950 F., somewhat above the average coking temperature of 800 F. to 850F., is introduced into still II) by pipe ll while simultaneously thereis introduced a heated fluid medium through pipe 39, it being understoodat the start of the operation that the lowermost cone ii is restrictedlyopen by plug 2'! while the remainder of cones I6 are wide open.

By restrictedly open is meant that there is suflicient space leftbetween the corrugations 33 of plug 21 and the corrugations of cone IEto permit the passage of the heated gaseous medium through theaccumulating heavy oil in cone I6, so that a cracking, stripping, andagitating step takes place.

The gas used for such step may be any hydrocarbon gas or vapor heated toa degree where it rapidly transfers its heat to the oil to effectcracking, or conversion, with the production of coke, such as the gasesor vapors from the stabilizer of another cracking unit because these areoften waste gases and are highly useful in the present process inasmuchas they not only serve as a heating and cracking medium but are believedto enter into the reaction to effect polymerization and be polymerizedor condensed with other hydrocarbons in the presence of coke as acatalyst to produce highly valuable lighterprodnets in the gasolineboiling range.

Further, hot hydrocarbon vapors discharged from the cracking tubes orreaction chamber of a so-called vapor phase cracking plant may bedirectly used because they are already at the desired high temperaturefor converting the heavy oil and the light gas oil and kerosene in suchvapors may undergo further cracking in their passage through-the driedand heated coke while solids carried by such vapors combine with thecoke and the so-called fixed gases mixed with the vapors undergo adegree of polymerization in the passage through the dried and heatedcoke.

Obviously, there is no substantial loss in using such vapors containingfixed'gases and comprising gasoline, kerosene and gas oil fractions.

If the oil is introduced through pipe II at temperatures between about750 F. and 950 F., with a tendency for very sudden temperature decreaseto as low as 700 F., due to the latent heat passer? and the endothermiccracking reaction, the gas will be introduced through pipe 39 attemperatures between about 900 F. and 1000 F., suflicient to cause thedesired cracking and coking.

The down-flowing heated oil is subjected to contact with the risingheated gas, or vapor, and in the lowermost cone I 6 the conversion tolight oil in vapor form and to coke continues as oil is deposited on.such lowermost cone I6 until a predetermined depth of reduced oil andcoke is reached at which time the next succeeding upper cone i6 isclosed to the restrictedly open position while the lowermost coneremains in its restrictedly open position. Then the continually risingheated gas in its passage through the reduced liquid and coke on thelowermost cone It continues until such reduced liquid is completelyconverted to lighter oil vapors and coke. Contrary to expectations, ithas been found that such coke accumulation, while relatively solid, isquite porous and permits the continuous passage of heated gastherethrough to agitate and convert the liquid stream continually beingdeposited on any upper cone Ill.

Inasmuch as-the rising heated gas passes very readily through the cokeaccumulation and inasmuch as such coke can be more easily removed fromthe various cones it when it is as thoroughly dried as possible by thecontinually rising heated gas, none of the cones IE will be opened untilthe supply of heated gas through pipe 39 is discontinued whichwill occurwhen a desired level has finally accumulated in the uppermost cone l6.

Such level in each cone i6 is best as a point where the expansibility ofthe corrugations in cone it is suflicient to free the coke whichthereupon fractures into easily dumpable small particles.

In like manner, each cone i6 is utilized up to a certain level ofaccumulated coke until the uppermost cone is thus used, whereupon theliquid and gaseous streams may be diverted to a second similar stillwhile the gaseous stream continues through the still i and then onthrough a second similar still until dry coke is formed on the uppermostcone of still I, after which the gaseous stream may be completelydiverted to the second still, thus making the operation substantiallycontinuous.

Manhole 38 may then be opened and'pressure applied, alternately,positive and negative, through pipes 18 and 35 alternately to expand andcontract all expansible surfaces and thereby loosen coke from suchsurfaces, leaving the interior ofstill 10 in substantially clean andnoncorroded condition for a fresh run.

Lowermost cone i5 may then be opened to expand such cone and dumpthecoke fractured by such action and any coke from the expansible surfacesinto the bottom of still l8 and out through manhole 38. This lowest coneis may be subsequently opened and closed several times to thoroughlyclean the surfaces and then left in a wide open position while eachsucceeding upper cone is operated in a similar manner, and so on untilall the cones are dumped, each cone in the rising series being left wideopen as it is cleaned. Manhole this then closed and the lowest cone isis closed to a restrictedly open position and still i0 is ready for asecond run when the second still in the series becomes charged withcoke. Any number of such stills as are desired or necessary may be usedin series with the usual pipe connectionaor cross-overs, for continuousoperation.

Cone I6 should have considerable conical slant when closed, about 40from horizontal is found suitable, so that a relatively small angularchange '(say, to about 60) will make a relatively great enlargement ofthe lower diameter and the cor rugations 33 of plug 21 should only givesuiiicient clearance to permit free passage of gas while preventingslippage of any liquid oil.

With these controls, the coke is substantially dry,'which makes it morereadily removable than wet coke and to this end the temperature of thedried coke should preferably be less than 1000 F. because it is muchmore brittle and fracturable by the apparatus than when above 1000 F.

In the modification in Fig. 2, similar instrumentalities are utilizedand operated by metal bellows di connected by pipes 42 to a source offluid under pressure which are thus operated without great manualefforts The operation may be-operated under superatmospheric pressure ofany desired degree but can be operated at atmospheric pressures,preferably between atmospere and pounds per square inch.

I claim as my invention: v

1. Appa'ratus'for recovering solids from liquids comprising: a towercontaining a flexible contact cone, means to supply liquid to an upperpart of said tower to flow downwardly into said cone, means to supply agas to a lower part of said tower, means to withdraw said gas from anupper part of said tower after passage through said cone, and. means toflex said cone.

'2. Apparatus for recovering solids from liquids comprising: a towercontaining interiorly a series of superimposed contact cones, means tosupply liquid to an upper part of said tower to flow downwardly intosaid cones, means to supply a gasto a lower part of said'tower, means towithdraw said gas from an upper part of said tower after passage throughsaid cones, and ex-' terior means to independently flex said cones.

3. Apparatus for recoveringsolids from liquids comprising: a towercontaining'a flexible contact cone, means to supply liquid to an upperpart of said tower to flow downwardly into said cone, means to supply agas to a lower part of said tower, means to withdraw said gas from anupper part of said tower after passage through said cone, means toretain said liquid in said cone, and means to flex said cone.

4. A tower comprising a shell having an inlet for liquid at an upperpart, an inlet for gas at a lower part, an outlet for gas at an upperpart, a flexible frusto-conical contacter fixed interiorly of said shellto receive said liquid and gas in direct countercurrent flow and adaptedto discharge its solid contents downwardly, means to maintain liquid insaid'contacter, and means to discharge the contents of said contacter.

I 5. A tower comprising a shell having an inlet for liquid at an upperpart thereof, an inlet for gas at a lower part thereof, an outlet forgas at an upper part thereof, a corrugated frusto-conical contacterfixed interlorly of said shell intermediate said liquid and gas inletsand having its smallest cross-sectional area discharging downwardly,means to maintain liquid in said contacter, and means to flex saidcontacter.

6. A tower comprising a shell having an inlet.

for liquid at an upper part thereof, an inlet for gas at a lower partthereof, an outlet for gas at an upper part thereof, a corrugatedfrustoconical contacter fixed interiorly of said shell intermediate saidliquid and gas inlets and having its smallest cross-sectional areadischarging downwardly, means to maintain liquid in said contactor,means to flex said contacter, a. plug in said smallest area adapted toretain material in said contacter, and means to expand said contacterabout said plug to discharge said material downwardly.

7. A tower comprising a shell having an inlet for liquid at an upperpart thereof, an inlet for gas at a lower part thereof, an outlet forgas at an upper part thereof, a corrugated frusto-conical contacterfixed interiorly of said shell intermediate said liquid and gas inletsand having its smallest cross-sectional area discharging downwardly,means to maintain liquid in said contacter, means to fiex saidcontacter, a corrugated plug in said smallest area adapted to retainmaterial in said contacter, and means to expand said contacter aboutsaid plug to discharge said material downwardly.

8. A tower comprising a. shell having an inlet for liquid at an upperpart thereof, an inlet for gas at a lower part thereof, an outlet forgas at an upper part thereof, a series of spaced corrugatedfrusto-conical contacters fixed interiorly of said shell intermediatesaid liquid and gas inlets and adapted to discharge their contentsdownwardly from the uppermost contacters to the lowest contacter, meansto maintain liquid in each contacter, and means to independently fiexeach contacter.

9. A tower comprising a vertical shell lined substantially throughoutits height with a flexible metal covering, a central shaft in saidshell, a series of frusto-conical flexible metallic contacters fixed atspaced intervals on the inner wall of said shell at their largecircumference, a series of plugs fixed on said shaft at intervals sospaced as to place each one of said plugs at about the interior of thesmall circumference of each of said contacters to partially ,close thedischarge of each of said contacters means to flex said metal covering,and means to expand each contacter independently about each plug. 10. Atower comprising a vertical shell lined substantially throughout itsheight with a flexible metal covering, a hollow central shaft in saidshell having a flexible metal covering, a series of frusto-conicalflexible metallic contacters fixed at spaced intervals on the inner wallof said shell at their large circumference, a series of plugs fixed onsaid shaft at intervals so spaced as to place each one of said plugs atabout the interior of the small circumference of each of said contactersto partially close the discharge of each of said contacters, independentmeans to flex said metal coverings, and means to expand each contacterindependently about each plug.

11. In a tower having an inlet for liquid at an upper portion thereof,an inlet for gas at a lower portion thereof, and an outlet for gas at anupper portion. thereof; a radially corrugated frusto-conical metalcontacter having a larger circumference fixed to the interior of saidtower with its smaller circumference at a lower level than said largercircumference and being positioned between said inlets for liquid andgas, and means to radially expand said contacter.

REED WALDO GARMAN.

